Method for forming filter arrangements; and, methods

ABSTRACT

A one aspect method of forming filter cartridge arrangements for use in air cleaners is provided. The method involves coiling a media pack with a central winding bead and cutting through the winding bead in the coiled media pack to form two media packs. An example filter arrangement is disclosed. In another aspect, a filter cartridge arrangement for use in air cleaners is provided. The filter cartridge arrangement includes a media pack including a plurality of inlet flutes and outlet flutes extending between first and second opposite flow faces and formed from an arrangement of facing sheet secured to corrugated sheet. An example cartridge includes a preform secured to the media pack. In some forms, the preform includes a grid arrangement extending across one of the flow faces. The grid arrangement can include a region of cured seal material positioned in contact with the first flow face, to secure the grid arrangement to the flow face.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.13/443,005, filed Apr. 10, 2012. U.S. Ser. No. 13/443,005 is acontinuation of U.S. Ser. No. 12/456,967, filed Jun. 24, 2009, which hasnow issued as U.S. Pat. No. 8,152,888, and was itself a continuation ofU.S. Ser. No. 11/271,112, which issued as U.S. Pat. No. 7,569,090. U.S.Ser. No. 11/271,112 having been filed Nov. 10, 2005 and claimed priorityto U.S. as provisional applications U.S. Ser. No. 60/627,603, filed Nov.12, 2004; and, U.S. Ser. No. 60/627,674, filed Nov. 12, 2004. U.S. Ser.No. 13/443,005; U.S. Ser. No. 12/456,967; U.S. Ser. No. 11/271,112;60/627,603; and, 60/627,674 each are incorporated herein by reference. Aclaim of priority to U.S. Ser. No. 13/443,005; U.S. Ser. No. 12/456,967;U.S. Ser. No. 11/271,112; U.S. provisional 60/627,603; and, U.S. Ser.No. 60/627,674 is made to the extent appropriate.

TECHNICAL FIELD

The present disclosure concerns air cleaners, for use, for example, forcleaning engine combustion air for vehicles and other equipment. Thedisclosure provides preferred components, assemblies and methods.

BACKGROUND

Gas streams often carry particulate material therein. In many instancesit is desirable to remove some or all of the particulate material fromthe gas flow stream. For example, air intake streams to engines formotorized vehicles or power generation equipment often includeparticulate material therein. The particulate material, should it reachthe internal workings of the mechanisms involved, can cause substantialdamage. It is therefore preferred, for such systems, to remove theparticulate material from the gas flow upstream of the engine or otherequipment involved. A variety of air cleaner arrangements have beendeveloped for particulate removal.

There has been a general trend for the utilization of air cleanerarrangements that utilize, as a media pack, z-filter mediaconstructions. In general z-filter media constructions can becharacterized as comprising a fluted sheet secured to a facing sheet,formed into a media pack configuration. Examples of z-filterarrangements are described in PCT Publication WO 97/40918, publishedNov. 6, 1997; U.S. Pat. Nos. 6,190,432 and 6,350,291; PCT application US04/07927, filed Mar. 17, 2004; U.S. Provisional application 60/532,783,filed Dec. 22, 2003; PCT Publication 03/095068, published Nov. 20, 2003;PCT publication WO 04/007054, published Jan. 22, 2004; PCT publicationWO 03/084641, published Oct. 16, 2003; and, U.S. Provisional Application60/543,804, filed Feb. 11, 2004; the complete disclosures of each ofthese cited references being incorporated herein by reference.

In general, improvements have been sought.

SUMMARY OF THE DISCLOSURE

According to the present disclosure, various features and techniques areprovided, for advantageous methods for preparing components for aircleaner arrangements. Some preferred components are provided, as well asassemblies which use those components. Also, methods of service and useare provided.

A preferred method, involving: (a) applying a winding bead to a centerof a corrugated sheet of a single facer strip; (b) coiling into a coil;and (c) cutting the coil through the winding bead, to form two mediapacks, is described. An example use of such a media pack is described inconnection with FIGS. 7-14, although alternative uses are possible.

In another aspect, the present disclosure relates to the provision of afilter cartridge arrangement comprising a media pack formed from afacing sheet secured to a corrugated sheet to define inlet flutes andoutlet flutes extending between first and second opposite flow faces.The cartridge includes a preform secured to the media pack and having agrid arrangement extending across one of the flow faces. A region ofcured seal material is positioned on the grid arrangement in contactwith the first flow face, to secure the grid arrangement to the flowface. A variety of additional specific preferred features are provided.In addition methods of assembly and use are provided.

In alternate applications or aspects, the described grid is an option,and a preferred preform having a region extending around the media pack,with a seal molded thereto, is described. Again methods of assembly anduse are provided.

Specific componentry, techniques and configurations disclosed herein canbe used together, as illustrated in the embodiments, to advantage.However they may be separately selected and used to create alternateadvantageous arrangements. Thus, there is no specific requirement forarrangements according to the present disclosure, that all of thevarious advantageous features disclosed be present.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, schematic, perspective view of z-filter mediauseable in arrangements according to the present disclosure.

FIG. 2 is a schematic, cross-sectional view of a portion of the mediadepicted in FIG. 1.

FIG. 3 is a schematic view of examples of various corrugated mediadefinitions.

FIG. 4 is a schematic view of a process for manufacturing mediaaccording to the present disclosure.

FIG. 5 is a cross-sectional view of an optional end dart for mediaflutes useable in arrangements according to the present disclosure.

FIG. 6 is a schematic view of a system using an air cleaner having afilter cartridge component according to the present disclosure.

FIG. 7 is an enlarged, side elevational view of a filter cartridgeuseable as a component in an air cleaner according to the presentdisclosure.

FIG. 8 is a schematic top plan view of the filter cartridge depicted inFIG. 7.

FIG. 9 is a schematic cross-sectional view taken along line 9-9, FIG. 8.

FIG. 10 is an enlarged, fragmentary, cross-sectional view of a portionof FIG. 9 showing the filter cartridge in sealing association withhousing componentry of an air cleaner, is use.

FIG. 11 is a perspective view of a preform component used in the filtercartridge of FIG. 7.

FIG. 12 is a top plan view of the preform component of FIG. 11.

FIG. 13 is a cross-sectional view taken along line 13-13, FIG. 12.

FIG. 14 is a cross-sectional view taken along line 14-14, FIG. 12.

FIG. 15 is a schematic process diagram of a step of sealing an adjacenttail end and lead end of a strip of z-filter media useable in anarrangement according to the present disclosure.

FIG. 16A is a schematic depiction of a step in a process of forming amedia pack according to the present disclosure.

FIG. 16B is a schematic depiction of a step following the step of FIG.16A.

DETAILED DESCRIPTION I. Z-Filter Media Configurations, Generally

Fluted filter media can be used to provide fluid filter constructions ina variety of manners. One well known manner is as a z-filterconstruction. The term “z-filter construction” as used herein, is meantto refer to a filter construction in which individual ones ofcorrugated, folded or otherwise formed filter flutes are used to definesets of longitudinal, typically parallel, inlet and outlet filter flutesfor fluid flow through the media; the fluid flowing along the length ofthe flutes between opposite inlet and outlet flow ends (or flow faces)of the media. Some examples of z-filter media are provided in U.S. Pat.Nos. 5,820,646; 5,772,883; 5,902,364; 5,792,247; 5,895,574; 6,210,469;6,190,432; 6,350,296; 6,179,890; 6,235,195; Des. 399,944; Des. 428,128;Des. 396,098; Des. 398,046; and, Des. 437,401; each of these fifteencited references being incorporated herein by reference.

One type of z-filter media, utilizes two specific media componentsjoined together, to form the media construction. The two components are:(1) a fluted (typically corrugated) media sheet; and, (2) a facing mediasheet. The facing media sheet is typically non-corrugated, however itcan be corrugated, for example perpendicularly to the flute direction asdescribed in U.S. provisional 60/543,804, filed Feb. 11, 2004,incorporated herein by reference.

The fluted (typically corrugated) media sheet and the facing media sheettogether, are used to define media having parallel inlet and outletflutes. In some instances, the fluted sheet and facing sheet are securedtogether and are then coiled to form a z-filter media construction. Sucharrangements are described, for example, in U.S. Pat. Nos. 6,235,195 and6,179,890, each of which is incorporated herein by reference. In certainother arrangements, some non-coiled sections of fluted media secured tofacing media, are stacked on one another, to create a filterconstruction. An example of this is described in FIG. 11 of U.S. Pat.No. 5,820,646, incorporated herein by reference.

For specific applications as described herein, coiled arrangements arepreferred. Typically, coiling of the fluted sheet/facing sheetcombination around itself, to create a coiled media pack, is conductedwith the facing sheet directed outwardly. Some techniques for coilingare described in U.S. provisional application 60/467,521, filed May 2,2003 and PCT Application US 04/07927, filed Mar. 17, 2004, each of whichis incorporated herein by reference. The resulting coiled arrangementgenerally has, as the outer surface of the media pack, a portion of thefacing sheet.

The term “corrugated” used herein to refer to structure in media, ismeant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. The term “corrugation” is notmeant to refer to flutes that are formed by techniques not involvingpassage of media into a bite between corrugation rollers. However, theterm “corrugated” is meant to apply even if the media is furthermodified or deformed after corrugation, for example by the foldingtechniques described in PCT WO 04/007054, published Jan. 22, 2004,incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by such techniquesas corrugating or folding) extending thereacross.

Serviceable filter element or filter cartridge configurations utilizingz-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context whatis meant is that the serviceable filter elements generally have an inletflow end (or face) and an opposite exit flow end (or face), with flowentering and exiting the filter cartridge in generally the same straightthrough direction. The term “serviceable” in this context is meant torefer to a media containing filter cartridge that is periodicallyremoved and replaced from a corresponding fluid cleaner. In someinstances, each of the inlet flow end and outlet flow end will begenerally flat or planar, with the two parallel to one another. However,variations from this, for example non-planar faces are possible.

A straight through flow configuration (especially for a coiled mediapack) is, for example, in contrast to serviceable filter cartridges suchas cylindrical pleated filter cartridges of the type shown in U.S. Pat.No. 6,039,778, incorporated herein by reference, in which the flowgenerally makes a turn as its passes through the serviceable cartridge.That is, in a 6,039,778 filter, the flow enters the cylindrical filtercartridge through a cylindrical side, and then turns to exit through anend face (in forward-flow systems). In a typical reverse-flow system,the flow enters the serviceable cylindrical cartridge through an endface and then turns to exit through a side of the cylindrical filtercartridge. An example of such a reverse-flow system is shown in U.S.Pat. No. 5,613,992, incorporated by reference herein.

The term “z-filter media construction” and variants thereof as usedherein, without more, is meant to refer to any or all of: a web ofcorrugated or otherwise fluted media secured to facing media withappropriate sealing to allow for definition of inlet and outlet flutes;or, such a media coiled or otherwise constructed or formed into a threedimensional network of inlet and outlet flutes; and/or, a filterconstruction including such media.

In FIG. 1, an example of media 1 useable in z-filter media is shown. Themedia 1 is formed from a corrugated (fluted) sheet 3 and a facing sheet4.

In general, the corrugated sheet 3, FIG. 1, is of a type generallycharacterized herein as having a regular, curved, wave pattern of flutesor corrugations 7. The term “wave pattern” in this context, is meant torefer to a flute or corrugated pattern of alternating troughs 7 b andridges 7 a. The term “regular” in this context is meant to refer to thefact that the pairs of troughs and ridges (7 b, 7 a) alternate withgenerally the same repeating corrugation (or flute) shape and size.(Also, typically in a regular configuration each trough 7 b issubstantially an inverse of each ridge 7 a.) The term “regular” is thusmeant to indicate that the corrugation (or flute) pattern comprisestroughs and ridges with each pair (comprising an adjacent trough andridge) repeating, without substantial modification in size and shape ofthe corrugations along at least 70% of the length of the flutes. Theterm “substantial” in this context, refers to a modification resultingfrom a change in the process or form used to create the corrugated orfluted sheet, as opposed to minor variations from the fact that themedia sheet 3 is flexible. With respect to the characterization of arepeating pattern, it is not meant that in any given filterconstruction, an equal number of ridges and troughs is necessarilypresent. The media 1 could be terminated, for example, between a paircomprising a ridge and a trough, or partially along a pair comprising aridge and a trough. (For example, in FIG. 1 the media 1 depicted infragmentary has eight complete ridges 7 a and seven complete troughs 7b.) Also, the opposite flute ends (ends of the troughs and ridges) mayvary from one another. Such variations in ends are disregarded in thesedefinitions, unless specifically stated. That is, variations in the endsof flutes are intended to be covered by the above definitions.

In the context of the characterization of a “curved” wave pattern ofcorrugations, the term “curved” is meant to refer to a corrugationpattern that is not the result of a folded or creased shape provided tothe media, but rather the apex 7 a of each ridge and the bottom 7 b ofeach trough is formed along a radiused curve. Although alternatives arepossible, a typical radius for such z-filter media would be at least0.25 mm and typically would be not more than 3 mm. (Media that is notcurved, by the above definition, can also be useable.)

An additional characteristic of the particular regular, curved, wavepattern depicted in FIG. 1, for the corrugated sheet 3, is that atapproximately a midpoint 30 between each trough and each adjacent ridge,along most of the length of the flutes 7, is located a transition regionwhere the curvature inverts. For example, viewing back side or face 3 a,FIG. 1, trough 7 b is a concave region, and ridge 7 a is a convexregion. Of course when viewed toward front side or face 3 b, trough 7 bof side 3 a forms a ridge; and, ridge 7 a of face 3 a, forms a trough.(In some instances, region 30 can be a straight segment, instead of apoint, with curvature inverting at ends of the straight segment 30.)

A characteristic of the particular regular, curved, wave patterncorrugated sheet 3 shown in FIG. 1, is that the individual corrugationsare generally straight. By “straight” in this context, it is meant thatthrough at least 70% (typically at least 80%) of the length betweenedges 8 and 9, the ridges 7 a and troughs 7 b do not changesubstantially in cross-section. The term “straight” in reference tocorrugation pattern shown in FIG. 1, in part distinguishes the patternfrom the tapered flutes of corrugated media described in FIG. 1 of WO97/40918 and PCT Publication WO 03/47722, published Jun. 12, 2003,incorporated herein by reference. The tapered flutes of FIG. 1 of WO97/40918, for example, would be a curved wave pattern, but not a“regular” pattern, or a pattern of straight flutes, as the terms areused herein.

Referring to the present FIG. 1 and as referenced above, the media 1 hasfirst and second opposite edges 8 and 9. When the media 1 is coiled andformed into a media pack, in general edge 9 will form an inlet end forthe media pack and edge 8 an outlet end, although an oppositeorientation is possible.

Adjacent edge 8 the sheets 3, 4 are sealed to one another, for exampleby sealant, in this instance in the form of a sealant bead 10, sealingthe corrugated (fluted) sheet 3 and the facing sheet 4 together. Bead 10will sometimes be referred to as a “single facer” bead, when it isapplied as a bead between the corrugated sheet 3 and facing sheet 4, toform the single facer or media strip 1. Sealant bead 10 seals closedindividual flutes 11 adjacent edge 8, to passage of air therefrom.

Adjacent edge 9, is provided sealant, in this instance in the form of aseal bead 14. Seal bead 14 generally closes flutes 15 to passage ofunfiltered fluid therein, adjacent edge 9. Bead 14 would typically beapplied as the media 1 is coiled about itself, with the corrugated sheet3 directed to the inside. Thus, bead 14 will form a seal between a backside 17 of facing sheet 4, and side 18 of the corrugated sheet 3. Thebead 14 will sometimes be referred to as a “winding bead” when it isapplied as the strip 1 is coiled into a coiled media pack. If the media1 were cut in strips and stacked, instead of coiled, bead 14 would be a“stacking bead.”

In some applications, the corrugated sheet 3 is also tacked to thefacing sheet 4 at various points along the flute length, as shown atlines 4 a.

Referring to FIG. 1, once the media 1 is incorporated into a media pack,for example by coiling or stacking, it can be operated as follows.First, air in the direction of arrows 12, would enter open flutes 11adjacent end 9. Due to the closure at end 8, by bead 10, the air wouldpass through the media shown by arrows 13. It could then exit the mediapack, by passage through open ends 15 a of the flutes 15, adjacent end 8of the media pack. Of course operation could be conducted with air flowin the opposite direction. However, in typical air filter applications,at one end or face of the media pack unfiltered air flow in, and at anopposite end or face the filtered air flow out, with no unfiltered airflow through the pack or between the faces.

For the particular arrangement shown herein in FIG. 1, the parallelcorrugations 7 a, 7 b are generally straight completely across themedia, from edge 8 to edge 9. Straight flutes or corrugations can bedeformed or folded at selected locations, especially at ends.Modifications at flute ends for closure are generally disregarded in theabove definitions of “regular,” “curved” and “wave pattern.”

Z-filter constructions which do not utilize straight, regular curvedwave pattern corrugation (flute) shapes are known. For example in Yamadaet al. U.S. Pat. No. 5,562,825 corrugation patterns which utilizesomewhat semicircular (in cross section) inlet flutes adjacent narrowV-shaped (with curved sides) exit flutes are shown (see FIGS. 1 and 3,of U.S. Pat. No. 5,562,825). In Matsumoto, et al. U.S. Pat. No.5,049,326 circular (in cross-section) or tubular flutes defined by onesheet having half tubes attached to another sheet having half tubes,with flat regions between the resulting parallel, straight, flutes areshown, see FIG. 2 of Matsumoto '326. In Ishii, et al. U.S. Pat. No.4,925,561 (FIG. 1) flutes folded to have a rectangular cross section areshown, in which the flutes taper along their lengths. In WO 97/40918(FIG. 1), flutes or parallel corrugations which have a curved, wavepatterns (from adjacent curved convex and concave troughs) but whichtaper along their lengths (and thus are not straight) are shown. Also,in WO 97/40918 flutes which have curved wave patterns, but withdifferent sized ridges and troughs, are shown.

In general, the filter media is a relatively flexible material,typically a non-woven fibrous material (of cellulose fibers, syntheticfibers or both) often including a resin therein, sometimes treated withadditional materials. Thus, it can be conformed or configured into thevarious corrugated patterns, without unacceptable media damage. Also, itcan be readily coiled or otherwise configured for use, again withoutunacceptable media damage. Of course, it must be of a nature such thatit will maintain the required corrugated configuration, during use.

In the corrugation process, an inelastic deformation is caused to themedia. This prevents the media from returning to its original shape.However, once the tension is released the flute or corrugations willtend to spring back, recovering only a portion of the stretch andbending that has occurred. The facing sheet is sometimes tacked to thefluted sheet, to inhibit this spring back in the corrugated sheet.

Also, typically, the media contains a resin. During the corrugationprocess, the media can be heated to above the glass transition point ofthe resin. When the resin then cools, it will help to maintain thefluted shapes.

The media of the corrugated sheet 3, facing sheet 4 or both, can beprovided with a fine fiber material on one or both sides thereof, forexample in accord with U.S. Pat. No. 6,673,136, incorporated herein byreference.

An issue with respect to z-filter constructions relates to closing ofthe individual flute ends. Typically a sealant or adhesive is provided,to accomplish the closure. As is apparent from the discussion above, intypical z-filter media, especially that which uses straight flutes asopposed to tapered flutes, large sealant surface areas (and volume) atboth the upstream end and the downstream end are needed. High qualityseals at these locations are critical to proper operation of the mediastructure that results. The high sealant volume and area, creates issueswith respect to this.

Attention is now directed to FIG. 2, in which a z-filter mediaconstruction 40 utilizing a regular, curved, wave pattern corrugatedsheet 43, and a facing (in this instance non-corrugated) sheet 44, isdepicted. The distance D1, between points 50 and 51, defines theextension of facing media 44 in region 52 underneath a given corrugatedflute 53. The length D2 of the arcuate media for the corrugated flute53, over the same distance D1 is of course larger than D1, due to theshape of the corrugated flute 53. For a typical regular shaped mediaused in fluted filter applications, the linear length D2 of the media 53between points 50 and 51 will generally be at least 1.2 times D1.Typically, D2 would be within a range of 1.2-2.0 time D1, inclusive. Oneparticularly convenient arrangement for air filters has a configurationin which D2 is about 1.25−1.35×D1. Such media has, for example, beenused commercially in Donaldson Powercore™ Z-filter arrangements. Hereinthe ratio D2/D1 will sometimes be characterized as the flute/flat ratioor media draw for the corrugated (fluted) media.

In the corrugated cardboard industry, various standard flutes have beendefined. For example the standard E flute, standard X flute, standard Bflute, standard C flute and standard A flute. FIG. 3, attached, incombination with Table A below provides definitions of these flutes.

Donaldson Company, Inc., (DCI) the assignee of the present disclosure,has used variations of the standard A and standard B flutes, in avariety of z-filter arrangements. These flutes are also defined in TableA and FIG. 3.

TABLE A (Flute definitions for FIG. 3) DCI A Flute: Flute/flat = 1.52:1;The Radii (R) are as follows: R1000 = .0675 inch (1.715 mm); R1001 =.0581 inch (1.476 mm); R1002 = .0575 inch (1.461 mm); R1003 = .0681 inch(1.730 mm); DCI B Flute: Flute/flat = 1.32:1; The Radii (R) are asfollows: R1004 = .0600 inch (1.524 mm); R1005 = .0520 inch (1.321 mm);R1006 = .0500 inch (1.270 mm); R1007 = .0620 inch (1.575 mm); Std. EFlute: Flute/flat = 1.24:1; The Radii (R) are as follows: R1008 = .0200inch (.508 mm); R1009 = .0300 inch (.762 mm); R1010 = .0100 inch (.254mm); R1011 = .0400 inch (1.016 mm); Std. X Flute: Flute/flat = 1.29:1;The Radii (R) are as follows: R1012 = .0250 inch (.635 mm); R1013 =.0150 inch (.381 mm); Std. B Flute: Flute/flat = 1.29:1; The Radii (R)are as follows: R1014 = .0410 inch (1.041 mm); R1015 = .0310 inch (.7874mm); R1016 = .0310 inch (.7874 mm); Std. C Flute: Flute/flat = 1.46:1;The Radii (R) are as follows: R1017 = .0720 inch (1.829 mm); R1018 =.0620 inch (1.575 mm); Std. A Flute: Flute/flat = 1.53:1; The Radii (R)are as follows: R1019 = .0720 inch (1.829 mm); R1020 = .0620 inch (1.575mm).

Of course other, standard, flutes definitions from the corrugated boxindustry are known.

In general, standard flute configurations from the corrugated boxindustry can be used to define corrugation shapes or approximatecorrugation shapes for corrugated media. Comparisons above between theDCI A flute and DCI B flute, and the corrugation industry standard A andstandard B flutes, indicate some convenient variations.

II. Manufacture of Coiled Media Configurations Using Fluted Media,Generally

In FIG. 4, one example of a manufacturing process for making a mediastrip corresponding to strip 1, FIG. 1 is shown. In general, facingsheet 64 and the fluted (corrugated) sheet 66 having flutes 68 arebrought together to form a media web 69, with an adhesive bead locatedtherebetween at 70. The adhesive bead 70 will form a single facer bead10, FIG. 1. An optional darting process occurs at station 71 to formcenter darted section 72 located mid-web. The z-filter media or Z-mediastrip 74 can be cut or slit at 75 along the bead 70 to create two pieces76, 77 of z-filter media 74, each of which has an edge with a strip ofsealant (single facer bead) extending between the corrugating and facingsheet. Of course, if the optional darting process is used, the edge witha strip of sealant (single facer bead) would also have a set of flutesdarted at this location.

Also, if tack beads or other tack connections 4 a, FIG. 1, are used,they can be made, as the sheets 64, 66 are brought together.

Techniques for conducting a process as characterized with respect toFIG. 4 are described in PCT WO 04/007054, published Jan. 22, 2004incorporated herein by reference.

Still in reference to FIG. 4, before the z-filter media 74 is putthrough the darting station 71 and eventually slit at 75, it must beformed. In the schematic shown in FIG. 4, this is done by passing asheet of media 92 through a pair of corrugation rollers 94, 95. In theschematic shown in FIG. 4, the sheet of media 92 is unrolled from a roll96, wound around tension rollers 98, and then passed through a nip orbite 102 between the corrugation rollers 94, 95. The corrugation rollers94, 95 have teeth 104 that will give the general desired shape of thecorrugations after the flat sheet 92 passes through the nip 102. Afterpassing through the nip 102, the sheet 92 becomes corrugated across themachine direction and is referenced at 66 as the corrugated sheet. Thecorrugated sheet 66 is then secured to facing sheet 64. (The corrugationprocess may involve heating the media, in some instances.)

Still in reference to FIG. 4, the process also shows the facing sheet 64being routed to the darting process station 71. The facing sheet 64 isdepicted as being stored on a roll 106 and then directed to thecorrugated sheet 66 to form the Z-media 74. The corrugated sheet 66 andthe facing sheet 64 are secured together by adhesive or by other means(for example by sonic welding).

Referring to FIG. 4, an adhesive line 70 is shown used to securecorrugated sheet 66 and facing sheet 64 together, as the sealant bead.Alternatively, the sealant bead for forming the facing bead could beapplied as shown as 70 a. If the sealant is applied at 70 a, it may bedesirable to put a gap in the corrugation roller 95, and possibly inboth corrugation rollers 94, 95, to accommodate the bead 70 a.

The type of corrugation provided to the corrugated media is a matter ofchoice, and will be dictated by the corrugation or corrugation teeth ofthe corrugation rollers 94, 95. One preferred corrugation pattern willbe a regular curved wave pattern corrugation of straight flutes, asdefined herein above. A typical regular curved wave pattern used, wouldbe one in which the distance D2, as defined above, in a corrugatedpattern is at least 1.2 times the distance D1 as defined above. In onepreferred application, typically D2=1.25-1.35×D1. In some instances thetechniques may be applied with curved wave patterns that are not“regular,” including, for example, ones that do not use straight flutes.

As described, the process shown in FIG. 4 can be used to create thecenter darted section 72. FIG. 5 shows, in cross-section, one of theflutes 68 after darting and slitting.

A fold arrangement 118 can be seen to form a darted flute 120 with fourcreases 121 a, 121 b, 121 c, 121 d. The fold arrangement 118 includes aflat first layer or portion 522 that is secured to the facing sheet 64.A second layer or portion 124 is shown pressed against the first layeror portion 122. The second layer or portion 124 is preferably formedfrom folding opposite outer ends 126, 127 of the first layer or portion122.

Still referring to FIG. 5, two of the folds or creases 121 a, 121 b willgenerally be referred to herein as “upper, inwardly directed” folds orcreases. The term “upper” in this context is meant to indicate that thecreases lie on an upper portion of the entire fold 120, when the fold120 is viewed in the orientation of FIG. 5. The term “inwardly directed”is meant to refer to the fact that the fold line or crease line of eachcrease 121 a, 121 b, is directed toward the other.

In FIG. 5, creases 121 c, 121 d, will generally be referred to herein as“lower, outwardly directed” creases. The term “lower” in this contextrefers to the fact that the creases 121 c, 121 d are not located on thetop as are creases 121 a, 121 b, in the orientation of FIG. 5. The term“outwardly directed” is meant to indicate that the fold lines of thecreases 121 c, 121 d are directed away from one another.

The terms “upper” and “lower” as used in this context are meantspecifically to refer to the fold 120, when viewed from the orientationof FIG. 5. That is, they are not meant to be otherwise indicative ofdirection when the fold 120 is oriented in an actual product for use.

Based upon these characterizations and review of FIG. 5, it can be seenthat a preferred regular fold arrangement 118 according to FIG. 5 inthis disclosure is one which includes at least two “upper, inwardlydirected, creases.” These inwardly directed creases are unique and helpprovide an overall arrangement in which the folding does not cause asignificant encroachment on adjacent flutes.

A third layer or portion 128 can also be seen pressed against the secondlayer or portion 124. The third layer or portion 128 is formed byfolding from opposite inner ends 130, 131 of the third layer 128.

Another way of viewing the fold arrangement 118 is in reference to thegeometry of alternating ridges and troughs of the corrugated sheet 66.The first layer or portion 122 is formed from an inverted ridge. Thesecond layer or portion 124 corresponds to a double peak (afterinverting the ridge) that is folded toward, and in preferredarrangements folded against, the inverted ridge.

Techniques for providing the optional dart described in connection withFIG. 5, in a preferred manner, are described in PCT WO 04/007054,incorporated herein by reference. Techniques for coiling the media, withapplication of the winding bead, are described in PCT application US04/07927, filed Mar. 17, 2004 and incorporated herein by reference.

Techniques described herein are particularly well adapted for use withmedia packs that result from coiling a single sheet comprising acorrugated sheet/facing sheet combination, i.e., a “single facer” strip.Certain of the techniques can be applied with arrangements that, insteadof being formed by coiling, are formed from a plurality of strips ofsingle facer.

Coiled media pack arrangements can be provided with a variety ofperipheral perimeter definitions. In this context the term “peripheral,perimeter definition” and variants thereof, is meant to refer to theoutside perimeter shape defined, looking at either the inlet end or theoutlet end of the media pack. Typical shapes are circular as describedin PCT WO 04/007054 and PCT application US 04/07927. Other useableshapes are obround, some examples of obround being oval shape. Ingeneral oval shapes have opposite curved ends attached by a pair ofopposite sides. In some oval shapes, the opposite sides are also curved.In other oval shapes, sometimes called racetrack shapes, the oppositesides are generally straight. Racetrack shapes are described for examplein PCT WO 04/007054 and PCT application US 04/07927.

Another way of describing the peripheral or perimeter shape is bydefining the perimeter resulting from taking a cross-section through themedia pack in a direction orthogonal to the winding axis of the coil.

Opposite flow ends or flow faces of the media pack can be provided witha variety of different definitions. In many arrangements, the ends aregenerally flat and perpendicular to one another. In other arrangements,the end faces include tapered, coiled, stepped portions which can eitherbe defined to project axially outwardly from an axial end of the sidewall of the media pack; or, to project axially inwardly from an end ofthe side wall of the media pack. Examples of such media packarrangements are shown in U.S. Provisional Application 60/578,482, filedJun. 8, 2004, incorporated herein by reference.

The flute seals (for example from the single facer bead, winding bead orstacking bead) can be formed from a variety of materials. In variousones of the cited and incorporated references, hot melt or polyurethaneseals are described as possible for various applications. Such materialsare also useable for arrangements as characterized herein.

When the media is coiled, generally a center of the coil needs to beclosed, to prevent passage of unfiltered air between the flow faces;i.e., through the media pack. Some approaches to this are referencedbelow. Others are described in U.S. Provisional 60/578,482, filed Jun.8, 2004; and U.S. Provisional 60/591,280, filed Jul. 26, 2004.

The media chosen for the corrugated sheet and facing sheet can be thesame or different. Cellulose fiber, synthetic fiber or mixed media fibermaterials can be chosen. The media can be provided with a fine fiberlayer applied to one or more surface, for example in accord with U.S.Pat. No. 6,673,136, issued Jan. 6, 2004, the complete disclosure ofwhich is incorporated herein by reference. When such material is used ononly one side of each sheet, it is typically applied on the side(s)which will form the upstream side of inlet flutes.

III. Example Arrangement A. General Background Regarding Air CleanerSystems

The principles and arrangements described herein are useable in avariety of systems. One particular system is depicted schematically inFIG. 6, generally at 150. In FIG. 6, equipment 152, such as a vehicle152 a having an engine 153 with some defined rated air flow demand, forexample in the range of 50 cfm to 2000 cfm (cubic feet per minute)(i.e., 1.4-57 cubic meters/minute) is shown schematically. Althoughalternatives are possible, the equipment 152 may, for example, comprisea bus, an over-the-highway truck, an off-road vehicle, a tractor, alight-duty or medium-duty truck, or a marine vehicle such as a powerboat. The engine 153 powers the equipment 152 upon fuel combustion. InFIG. 6, air flow is shown drawn into the engine 153 at an air intake atregion 155. An optional turbo 156 is shown in phantom, as optionallyboosting the air intake to the engine 153. The turbo 156 is showndownstream from an air cleaner 160, although alternate arrangement arepossible.

The air cleaner 160 has a filter cartridge 162 and is shown in the airinlet stream to the engine 153. In general, in operation, air is drawnin at arrow 164 into the air cleaner 160 and through the filtercartridge 162. Upon passage through the air cleaner 160, selectedparticles and contaminants are removed from the air. The cleaned airthen flows downstream at arrow 166 into the intake 155. From there, theair flow is directed into the engine 153.

In a typical air cleaner 160, the filter cartridge 162 is a serviceablecomponent. That is, the cartridge 162 is removable and replaceablewithin the air cleaner 160. This allows the cartridge 162 to beserviced, by removal and replacement, with respect to remainder of aircleaner 160, when the cartridge 162 becomes sufficiently loaded withdust or other contaminant, to require servicing.

B. An Example Air Filter Cartridge

The example air filter cartridge and components depicted in FIGS. 7-15are also described in a co-filed U.S. Provisional application entitled“Filter Arrangements; Housings; Assemblies; and, Methods” filed Nov. 12,2004, identifying Ben Nelson as inventor and filed under Express Mail#EV 541525103 US; the complete disclosure of which is incorporatedherein by reference.

The reference numeral 200, FIG. 7, indicates a filter cartridgeaccording to the present disclosure. The filter cartridge 200 is aserviceable component of an air cleaner system. That is, in a typicalair cleaner system, the filter cartridge 200 can be installed and beremoved for servicing, for example by replacement, in time. The filtercartridge 200 may be used as cartridge 162, FIG. 6.

Referring to FIG. 7, filter cartridge 200 comprises media pack 202 andhousing seal arrangement 203. In general, the media pack 202 comprisesz-filter media as generally described above. An example would be acoiled arrangement of z-filter media comprising a fluted sheet securedto a facing sheet, with the facing sheet facing outwardly in the coil.The arrangement would define a plurality of inlet and outlet flutesextending between opposite flow faces. Referring to FIG. 7, the oppositeflow faces are indicated generally at 205, 206. The filter cartridge 200can be configured for preferred flow in either direction. However for atypical application, when installed in an air cleaner, filter cartridge200 will be configured for air flow in the direction of arrows 208,i.e., with face 205 being an inlet flow face and face 206 being an exitflow face. (A center of the coil, as discussed below, should be closedto prevent unfiltered air flow through the media pack 202, i.e., betweenfaces 205, 206.)

For the particular media pack 202 depicted, flow faces 205 and 206 areeach generally planar. Alternate configurations are possible, but planarfaces are convenient for use with the principles characterized herein.

Still referring to FIG. 7, at 210 a tail end of the media coil isdepicted. For the example depicted, the tail end 210 is shown sealedclosed. In particular, tail end 210 is sealed underneath a sealantregion 211. The particular sealant region 211 comprises a hot meltsealant, polyurethane sealant or other sealant applied over tail end210.

Referring to FIG. 8, the particular media pack 202 depicted, has agenerally cylindrical shape, i.e., circular cross-section defining acylindrical outer perimeter 202 a. The principles described herein canbe used with a variety of shapes of media packs, including ones having agenerally oval shape, with two curved ends separated by sides, the sideseither being curved or straight (as in a racetrack shaped element). Ofcourse still other, alternative, shapes are possible.

Referring to FIGS. 8 and 9, coiled media pack 202 defines a central core215 discussed below. Again, the core 215 is preferably closed, to flowof unfiltered air therethrough.

Referring to FIG. 7, housing seal arrangement 203 is positioned andconfigured to provide for a seal between cartridge 200 and an aircleaner housing, when cartridge 200 is installed in use, to inhibit airfrom passing from adjacent face 205 to face 206, without passage throughthe media pack 202. To accomplish this, two features are required aboutthe housing seal arrangement 203: (a) it is positioned and configuredfor sealing against housing componentry of an air cleaner; and (b) it issealed to the media pack 202 such that leakage of flow between the sealarrangement 203 and the media pack 202 is inhibited.

A preferred housing seal arrangement 203 is characterized herein, foraccomplishing of both these features.

In addition, under use conditions with air flow and thus pressure in thedirection of arrow 208, a media pack 202 formed from a coil of singlefacer material, can, in some instances, tend to deform in the downstreamdirection, i.e., in the direction of arrow 208. The tendency to deformis in part a factor of: material chosen for the media; material chosenfor the single facer seal and winding bead; and conditions of use. Insome instances it is desirable to provide a mechanical supportarrangement in the housing, on the media pack or both, to help resistthis deformation. The particular air filter cartridge 200 depictedherein, includes a mechanical support arrangement to resist suchtelescoping of the media pack 202, at a location adjacent end face 205.When filter cartridge 200 is configured for flow face 205 to be anupstream flow face, this presents the situation of having the mechanicalsupport arrangement (to resist telescoping) being positioned at theupstream end of the media pack 202, as described below.

Attention is now directed to FIG. 10, in which an enlarged, fragmentary,cross-sectional view of a portion of filter cartridge 200 is depicted incross-sectional view. In FIG. 10 at 220, portions of a housingarrangement in which the serviceable filter cartridge 200 would bepositioned, for use, are shown in broken lines. In particular thehousing arrangement comprises inlet section 221 and outlet section 222,with a corresponding filtering flow in the direction of arrows 224.

Referring still to FIG. 10, at 225 a region of seal material comprisinga portion of housing seal arrangement 203 is depicted. Region 225 isconfigured: (a) to engage a portion of an outside surface 202 a of mediapack 202, as shown at interface 227; and (b) to define a housing seal.

In general, region of seal material 225 would comprise a molded-in-placeregion, formed from a resin as described, generally, below. Typically aresin will be chosen to provide region 225 with an appropriate firmnessor hardness, for installation in an air cleaner. A variety of materialscan be used. Examples would include urethane. Preferred urethanes arefoamed urethanes, typically ones that increase in volume at least 40%,preferably at least 80%, during care, although alternatives arepossible. Although alternatives are possible, examples of useableurethanes include those having an as-molded density of no greater than30 lbs/cu.ft. (0.48 g/cc), typically no greater than 22 lbs/cu.ft (0.35g/cc) and usually within the range of 10 lbs/cu.ft (0.16 g/cc)−22lbs/cu.ft. (0.35 g/cc). Such urethanes typically have a hardness, ShoreA, of no greater than 30, typically no greater than 25 and usuallywithin the range of 12 to 22. Of course urethane materials outside ofthe ranges stated are useable. The particular materials identified,however, are advantageous with respect to many systems, since thematerials are both robust and sufficiently soft so as to besubstantially compressible, under hand forces, to form a seal with thehousing arrangement.

Herein above when it is stated that a region is “molded-in-place,” it ismeant that the material is molded in place in the filter cartridge orfilter cartridge arrangement, from a resin. That is, the material is notpreformed as a structure, and then attached to a portion of the filtercartridge.

In some instances, portions of a “molded-in-place” seal arrangement, maybe characterized as “molded integral.” When used in this manner, theterm “molded integral” is meant to refer to two portions ofmolded-in-place material, which are molded in place at the same time andfrom an integral resin pool, i.e., resin material that, before cure, iscontinuous without an interface completely separating sections.

Still referring to FIG. 10, at 230 an optional label is shown attachedto a portion of the outer periphery to 202 a media pack 202. It is notedthat in FIG. 10, label 230 is shown embedded within a portion of region225, so that region 225 helps secure the label 230 in place. It is alsonoted that the label 230 is not embedded so far within region 225 thatlabel 230 completely blocks direct interface between region 225 andmedia pack 202 therearound, for example as shown at interface 227. Thus,a seal leak between region 225 and media pack 202 is inhibited.

In the context of the previous paragraph the term “direct interface” ismeant to refer to an interface between the two identified components,with nothing therebetween at the interface. In the instance described,there is reference to the molded-in-place region of seal material 225and its interface 227 with the media pack 202. What is meant is thatthere is preferably a continuous perimeter of such interface, around themedia pack 202, at some location, not interfered with by the label 230.Typically the direct interface with the media pack 202 will be with thesingle facer sheet itself, or with material, such as a sealant orprotective material, applied to the single facer sheet.

Still referring to FIG. 10, outer periphery 225 a of region 225 is shownwith three general surfaces: (a) a first axially directed surface 232;(b) a second, generally opposite, axially directed surface 233; and, (c)an outer annular, radially directed surface 235 extending there between.

The term “axial” in this context, is meant to refer to a surface whichgenerally faces a direction of extension of a central axis 240 (FIG. 9)of filter cartridge 200. For the particular region 225 described,surface 232 generally faces the same direction as flow face 205; and,surface 233 generally faces the same direction as flow surface 206. Itis noted that for the example shown, surface 233 is not preciselyparallel with end faces 205, 206 respectively. However in general itfaces the same direction. Typically, when media pack end faces 205, 206are planar as for the example shown, regions 233, 232 will be viewed asfacing the same direction as the end faces, provided that extend at anacute angle, relative to a side of the media pack extending between theend faces 205, 206, within the range of 75°-90°, typically within therange of 80°-90°, and usually at least 85°.

Herein the term “radial” is indicated generally to refer to a directiontoward or away from central axis 240, FIG. 9. Thus, annular surface 235is a radially outwardly directed surface.

Region 235 can be configured to form a variety of types of seal with anair cleaner, in use. The particular region 235 depicted is configured toform a radial seal with an air cleaner housing; the seal involving aportion of annular surface 235. This can be understood by reference toFIG. 10.

In particular, when filter cartridge 200 is positioned within an aircleaner housing 220, components or sections 221 and 222 are clampedtoward one another. Region 235 is positioned for engagement with the aircleaner as follows: surface 232 will engage shelf 221 a of air cleanerinlet section 221; surface 233 will engage shelf 222 a of air cleaneroutlet section 222; and, region 235 a of annular surface 235 will form aradial seal with the housing, in this instance with extension 222 b ofoutlet section 222. In FIG. 10, region 235 a is shown not distorted fromthe sealing force, and thus is depicted overlapping a portion of region222 b. In an actual installation with region 235 comprising asufficiently compressible material; region 235 a would be deformedinwardly toward the media pack 202 in forming the radial seal.

It is noted that for the example shown, region 235 a is configured toengage the outlet portion or section 222. Thus the seal formed 235 a isdownstream of the interface 242 between the two housing portions 221,222. This means that any leakage at this interface, will not leak pastthe seal 235 a, to the downstream or outlet end of the housing.

Sections 222 and 221 can be configured to bottom out, or engage oneanother, after a desired amount of pinching toward one another duringassembly.

It is noted that for the particular region 225 depicted, surface 235tapers generally outwardly in size (or thickness out from the media pack202) in extension toward an apex in region 235 a, from surface 232; andtapers inwardly in size (or thickness out from the media pack 202) inextension from region 235 a toward surface 233. This can help withformation and installation, although a variety of surface contours ordefinitions can be provided. At apex 235 a, material within region 225would be compressed the greatest extent, during radial sealing.

Still referring to FIG. 10, attention is directed to preform 250. Hereinthe term “preform” in this context is meant to refer to a component ofthe filter cartridge 202, other than the media pack 202, which is formedand then brought into contact with the media pack 202 before region 225is molded in place. Thus preform 250 is secured to the media pack 202,in part, by molded-in-place region of seal material 225. For theparticular filter cartridge 200 depicted, preform 250 is a ringstructure 253 defining: projection 255 which surrounds the media pack202; outwardly projecting annular radial lip 256, which is embeddedwithin region 225 of seal material; and grid work 257, which extendsacross flow face 205 as discussed below. The shape defined by ringstructure 253 will generally correspond to the outer peripheral shape ofthe media pack 202. Thus, in the example shown, ring structure 253defines a generally circular outer perimeter.

Still referring to FIG. 10, it is noted that a portion of preform 250 islocated between at least a portion of radial seal area 235 a, and themedia pack 202. This will be preferred in some applications, since itensures there is a rigid preform structure backing up at least some ofthe compression of the radial seal material in this region.

The preform 250 used in cartridge 200, FIGS. 7 and 10, is shown indetail in FIGS. 11-13, separated from the cartridge. Referring to FIG.11, the general components of the preform 250 include: (1) ringstructure 253 having projection 255; (2) lip 256; and, (3) grid work257.

Referring to FIG. 12, lip 256 is shown having an aperture arrangement,in this instance comprising a plurality of apertures 260, therein, whichextend through lip 256. Aperture arrangement or aperture 260 allow resinto flow through, as region seal material 225 is molded-in-place. In sucha molding operation, preform 250 will become mechanically secured withinregion of seal material 225, since the material 225 will cure withextension through the aperture arrangement 260. Although alternativesare possible, the orientation of the apertures 260 reflect a preferredmolding operation in which the preform 250 is oriented in a mold in thegeneral orientation as shown in FIG. 10, with the resin material whichforms region 225 rising upwardly, during cure. This will be discussedfurther below.

Referring to FIG. 10, in the cross-section of preform 250 shown in FIG.13, it is noted that projection 255 includes an outwardly projectingsurface portion 255 a which is directed obliquely away from media pack202. This helps media pack 202 insertion into projection 255. It alsoprovides location for resin flow to ensure engagement with media pack202 at interface 227, inhibiting leakage between the media pack 202 andthe preform 250.

Referring to FIG. 11, grid work 257 is recessed from edge or tip 255 bof projection 255. In a typical cartridge 200, media pack 202 would beinserted past edge 255 b until the media pack flow surface 205 abutsgrid work 257. Thus, grid work 257 will typically be configured todefine, and extend across, a surface corresponding to flow surface 205.In the example, the flow surface 205 is planar, so the grid work 257 isplanar in this region, as shown.

Referring to FIG. 11, the example grid work 257 shown generally definescenter 265 and radial legs 266. The center 265 generally defines a cup267 with a side wall 267 a defining an open region with a bottom 265 a,FIG. 12, having apertures 265 b therethrough. The apertures 265 b areflow apertures, allowing resin to flow therethrough during formation ofthe cartridge 200, to provide a mechanical connection at this point, asdescribed below. The cup 267 is oriented with bottom 265 a spaced fromthe media pack, in the cartridge 200.

The radial legs 266 generally each comprise side walls 266 a, 266 b(FIG. 14) and a center base 266 c. The center base 266 c has resin flowapertures 266 d therein, FIG. 12, to allow resin flow therethrough fordefinition of a mechanical interaction, during formation of cartridge200, discussed below. The opposite side walls 266 a, 266 b generallydefine a trough region 268 to contain resin adjacent a media pack flowsurface 205, as discussed below. For the particular arrangement shown,FIG. 11, the trough regions 268 comprise a plurality of (in the exampleshown four) spokes terminating at ring 250 a defined by preform 250.

For an arrangement utilizing preform 250, FIGS. 11-13, applied to forman arrangement according to FIG. 10, two molded-in-place regions of sealor resin material would be generated:

1. a first corresponding to region 225 which forms (a) a seal to themedia pack; (b) a housing seal arrangement; and, (c) mechanical securingof the form 250 around an outer perimeter thereof; and,

2. a second shown at 269, FIG. 10, which is positioned within cup 265and troughs 268, FIG. 11, and which engages the media pack at surface205, to inhibit telescoping.

The preform 250 could be configured so that these regions (225, 269) areintegrally molded with one another, if desired, for example by havingapertures in ring 250 a, FIG. 11, the ends of the troughs 268. However,with the particular preform 250 depicted, could generate these tworegions as separate from one another, not having a direct interfacebetween the two.

Construction of a cartridge 200 will generally be as follows, a moldwill be provided with: a mold cavity having an outer surface configuredto form all or a portion of annular surface 235 of region 225; and, abottom configured to receive preform 250 therein. The preform 250 wouldbe positioned within the mold cavity. Resin would be poured into themold cavity within: cup 265, trough regions 268 and an annular portionof the mold cavity configured to form region 225. The media pack wouldthen be inserted in position within projection 255. (In some instancesthe media pack could be inserted before the resin to form region 225 ispoured.) The mold would typically include a cover positioned around themedia pack, to define resin rise such that, for example, surface 233would be defined. The resin would be allowed to rise and cure. Duringthis process:

-   -   1. the resin would flow through apertures 260, securing the        preform in position;    -   2. the resin would flow through apertures 265 a and 266 a,        further securing the preform 250 in position; and,    -   3. the resin would rise within the trough arrangement 268        defined by legs 257, to engage the media pack surface 205, in a        region of the media pack 202 in overlap with legs 257. Spread        across the surface 205 would be inhibited, by engagement between        the media pack surface 205 and the grid work arrangement 257.        However resin rise into engagement with the media pack 202, and        then cure, would physically secure surface 205 to the grid work        257. This would stabilize surface 205 against telescoping,        during use.

After cure, of course, the cartridge 200 could be separated from themold arrangement.

Referring to FIG. 9, it is noted that resin material positioned withincentral cup 267, FIG. 12, is positioned to rise into core 215 at leastpartially, to close the core 215 against flow therethrough, ofunfiltered air.

When the media pack is configured for use such that the upstream end orface 205 is the face across which the grid of the preform 250 extends,and thus is the face across which the grid is secured to the face by thecured resin, the result is a media pack which in use is inhibited fromtelescoping at least in part by grid work extending across the upstreamend, in contact with the media pack. In some instances this can beadvantageously used to avoid the introduction of grid work or otherstructure on the downstream end of the media pack, either on the mediapack or in the housing, to inhibit telescoping.

Either end of the media pack can be used as the upstream end, even whenthe media pack has darted flutes at one end corresponding to the flutesof FIG. 5. However when darted flutes according to FIG. 5 are used, itmay in some instances be convenient to position the opposite end of themedia pack as upstream face 205.

The choice of which end of the media pack is used at the upstream face,for engagement with the preform 250, the choice will be determined bysuch factors as: (a) if fine fibers is applied to only facing sheet,which end would result in the inlet flutes having the fine fiberapplication on the upstream surface; (b) which end face is smoother andmore easy for engagement by the seal material and the grid work, duringformation; and (c) which end has a winding bead, when factors of themanufacturing require (or prefer) winding bead overlap with certainportions of the structure added in association with the preform 250 andmolded polymer (typically urethane) features.

C. Lead End Seal and Tail End Seal

As indicated above, and generally when the media pack 202 is formed bycoiling a single facer strip of fluted sheet secured to facing sheet,seals are needed (or at least preferred) at the lead end and the tailend of the coil. With respect to the tail end, a possibility wasdiscussed above in connection with FIG. 7, of applying a sealant 211over the tail end 210, to provide the seal. Alternatives are possible.

In general, at the lead end and tail end, two types of seals can be ofconcern: (a) a seal within the single facer strip, between the flutedsheet and the facing sheet, along the lead and tail edges; and, (2) aseal between the end of the lead end or tail end and the nextoverlapping (or overlapped) coil.

Whether or not seals at these locations is of concern, will in partdepend on the nature of the media pack 202 and the location of otherseals.

Referring to FIG. 9, if the winding bead for the media pack 202 islocated adjacent surface 205 in overlap with housing seal arrangement203, leakage of unfiltered air between coils, adjacent surface 205, withair flow in the direction of arrow 208 will not be a problem. This isbecause the winding bead provides a seal at this location, so air cannotpass between layers of the coil. Thus, at the lead end or tail end ofthis region, the issue of concern would be the sealing of the flutedsheet to the facing sheet along this edge. With respect to the tail end,FIG. 7, this is managed by sealant 211. An issue relates to sealing ofthis portion of the media pack, at the lead end positioned within core215.

One approach would be to pour enough sealing material within the core215, FIG. 9, filling up the core and sealing the lead end. Approachesrelated to this are described for example in U.S. Provisional 60/578,482filed Jun. 8, 2004, incorporated herein by reference.

Another approach would be to provide the lead end (or both the lead endand the tail end) with edge seals of the type described in U.S.Provisional 60/591,280 filed Jul. 26, 2004, at FIG. 10. In general theseare described herein in connection with FIG. 15, as follows.

Referring to FIG. 15, at 280 a continuous strip of single facer materialis shown comprising corrugated (or fluted) sheet 281 secured to facingsheet 282. At station 285 a strip 286 of material are shown insertedinto at least one, and typically into two adjacent, corrugations(flutes) 287. The strips 286 would typically comprise an ultrasonicallyweldable polymeric material, inserted as a long strip for examplesimilar to a fish line. Useable materials include nylon, polypropylenesand/or polyethylene lines, typically 0.025-0.080 inch in diameter (0.6-2mm). The strips 286 preferably extend completely through corrugations287.

At station 290 the ultrasonic (sonic) welding horn 291 is shown havingwelded and compressed corrugations (flutes) 287 closed, at region 295.The strips 286, will have been deformed and welded, to seal thecorrugations (flutes) 287 closed.

At station 300, the resulting strip 301 is shown cut into section 303and 304. As an example, section 303 could comprise a strip of singlefacer material with sealed tail end 305, and section 304 could comprisea strip of single facer material with lead end 306.

Each of the strips would be sealed at its opposite ends, by a similarprocess. Each of the strips could then be coiled to form the media packcoil 202, FIG. 7.

Of course alternate methods of sealing the lead and tail ends can beused, including application of a sealant such as a hot melt or otherliquid sealant across the material at these locations.

When such seals as described above in connection with FIG. 15 are usedas lead end seals and tail end seals; and, the winding bead is adjacentthe inlet face 205 and overlapped by the housing seal arrangement 203,it is noted that a seal strip as shown at 211, FIG. 7, along the tailend 210 is not needed. The tail end 210 can simply be tacked down by anadhesive label or other structure, for example. The label can be chosento have a portion positioned to be shown at FIG. 10 at label 230, whichis embedded within the molded region 225, to help secure the label inposition, through the lifetime of the resulting filter cartridge 200.

D. Alternate Single Facer Formation, FIGS. 16A-B

In some instances, it may be desirable to provide the media pack 202with an end face, for attachment of the preform 250, that is a clean,cut, planar surface. This would correspond, for example, to surface 205,FIGS. 7-10.

One approach to formation of a media pack with such a surface, wouldinvolve a step of cutting through an edge seal, to form the surface.This could be done by cutting through the sealant material along an edgeof a media pack formed by coiling the media 1 depicted in FIG. 1, ifdesired. An issue with this approach is that it wastes material. Also,control to form a planar surface may be limited by the ability to coilproperly.

Another approach to forming a media pack, but avoiding these types ofissues, is shown in FIGS. 16A and 16B. Referring to FIG. 16A, at 330 astrip of material comprising a corrugated sheet 331 secured to facingsheet 332 is shown. In FIG. 16A, strip 330 is shown fragmented, withfeatures at the opposite edges 334, 335 not being viewed, since only acentral portion 330 a of strip 330 is depicted. At 341, a winding beadof sealant material 342 is being shown applied by dispenser 343, in thisinstance to a corrugated surface 331, opposite the facing sheet 332.

This application is to a central region, spaced from opposite edges(generally near 334, 335). Although the application is not necessarilyat a geometric center between edges 334, 335, it typically would be. Theterm “central region” and variants thereof, in this context, is notmeant to require location at a geometric center, unless so stated.Following the step of FIG. 16A, the resulting strip 330 would be coiled.

In FIG. 16B, a coil 351 formed from strip 330 is depicted. The oppositeedges 334 and 335 are viewable. In FIG. 16B, the coil 351 is shown beingcut along line 355, at a location 360 by cutting apparatus 361. Line 355overlaps winding bead 341. After the cutting process, two media packswill be formed at 370, 371, each having a face resulting from thecutting at line 355, which is a smooth planar surface through thewinding bead 341. The media packs 370, 371 can be the same size or havedifferent lengths, depending on whether the cut line 360 is in the exactcenter, or offset. The resulting packs 370, 371, can be used in a filtercartridge according to FIG. 7, or in an alternate type of z-filtercartridge.

Such a smooth planar surface can be particularly desirable, forattachment of a preform such as preform 250, to form filter cartridge isaccording to the processes described hereinabove.

In FIG. 16B, it is noted that along sides 334, 335, edge single facerseals 334 a and 335 a, respectively are shown.

It is noted that the process discussed in connection with FIG. 16B isoperated on a coiled media pack having a generally circular outerperimeter. Of course the approach can be applied to any coiled mediaarrangement, including ones that are coiled having an oval exterior,with two opposite curved ends and two opposite sides; including ovalones in which the two opposite sides are also curved or in which the twoopposite sides are generally straight and parallel to one another.

1-4. (canceled)
 5. A filter cartridge arrangement comprising: (a) amedia pack comprising a plurality of inlet flutes and outlet flutesextending between first and second, opposite, flow faces and formed froman arrangement of facing sheet secured to corrugated sheet; (i) themedia pack having an outer periphery; (b) a preform secured to the mediapack and having a grid arrangement extending across a selected one ofthe flow faces; the preform including an aperture arrangementtherethrough; (c) a region of cured seal material positioned on the gridarrangement; the region of cured seal material including: portionsextending through the aperture arrangement; and, a portion defining aradially outwardly directed housing radial seal. 6-10. (canceled)
 11. Afilter cartridge arrangement comprising: (a) a media pack comprisingfluted media secured to facing media and defining first and second,opposite, flow faces with inlet and outlet flutes extendingtherebetween; (b) a preform secured to the media pack and having anaperture arrangement therethrough; and, (c) a region of cured sealmaterial positioned on the preform; (i) the region of cured sealmaterial including material extending through the aperture arrangement;and, (ii) the region of cured seal material including a portion defininga housing seal arrangement having a radially directed seal surface. 12.A filter cartridge arrangement comprising: (a) a media pack comprisingfluted media secured to facing media and defining a first and second,opposite, flow faces with inlet and outlet flutes extendingtherebetween; (b) a preform including a seal support; (c) a region ofcured material securing the preform to the media pack; (i) the region ofcured material including a molded-in-place portion: located between aportion of the preform and a selected one of the flow faces; and,forming a mechanical connection between the preform and the selected oneof the flow faces; and, (d) a housing seal.
 13. A filter cartridgearrangement according to claim 12 wherein: (a) the housing seal ismolded-in-place.
 14. A filter cartridge arrangement according to claim12 wherein: (a) the housing seal includes an annular surface positionedto form a radial seal with a housing, in use.
 15. A filter cartridgearrangement to claim 14 wherein: (a) a portion of the housing seal thatincludes the annular surface positioned to form a radial seal with ahousing has a hardness, Shore A, of no greater than
 25. 16. A filtercartridge arrangement according to claim 12 wherein: (a) the housingseal includes a surface positioned to be compressed, in use, against afirst of two opposing surface portions of two separable housing sectionswhen the two housing sections are pinched toward one another.
 17. Afilter cartridge arrangement according to claim 12 wherein: (a) themedia pack comprises a coiled arrangement of fluted media secured tofacing media.
 18. A filter cartridge arrangement according to claim 17wherein: (a) the media pack has an oval shape.
 19. A filter cartridgearrangement according to claim 12 wherein: (a) the region of curedmaterial that includes a molded-in-place portion located between aportion of the preform and a selected one of the flow faces, is moldedintegral with the housing seal.
 20. A filter cartridge arrangementaccording to claim 12 wherein: (a) the preform includes aperturestherethrough; and, (b) a portion of molded-in-place material extendsthrough the apertures.
 21. A filter cartridge arrangement according toclaim 12 including: (a) a portion of molded-in-place materialsurrounding the media pack and secured thereto.
 22. A filter cartridgearrangement according to claim 12 wherein: (a) the housing seal ispositioned to engage a housing at a location surrounding the media pack.23. A filter cartridge arrangement according to claim 12 wherein: (a)the preform includes a grid arrangement extending across the selectedone of the flow faces.
 24. A filter cartridge arrangement according toclaim 12 wherein: (a) the media pack includes a central core closed bymolded-in-place material formed from a resin that rose during cure. 25.A filter cartridge arrangement according to claim 12 wherein: (a) theselected one of the flow faces is an inlet flow face.
 26. A filtercartridge arrangement according to claim 12 wherein: (a) themolded-in-place portion of the region of cured material comprises foamedpolyurethane.
 27. A filter cartridge arrangement according to claim 12wherein: (a) the molded-in-place portion of the region of cured materialcomprises a resin that increased in volume by at least 40% during cure.28. A filter cartridge according to claim 12 wherein: (a) no portion ofthe region of cured material located between a portion of the preformand a selected one of the flow faces is integral with any portion ofmolded-in-place material that surrounds the media pack.
 29. A filtercartridge according to claim 12 wherein: (a) the preform includes aportion surrounding, and projecting radially away from, the media pack.